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Campaign Walkthrough

Portal 2 has nine chapters spanning three narrative acts. The game moves from modern test chambers through abandoned 1950s-era facilities and into a collapsing lab run by a rogue AI. This walkthrough covers every chapter with solutions for the major puzzle stumbling points.

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If this is your first playthrough, try every puzzle yourself before reading solutions. Portal 2's puzzles are designed to be solved through observation, and the writing between puzzles is the best part of the game. Come back here when you are stuck.

Act 1: Modern Aperture (Chapters 1 through 5)​

Chapter 1: The Courtesy Call​

You wake up in a motel-like relaxation vault. Follow the on-screen prompts to look around and go back to sleep. Time passes. You wake up again. The room is wrecked, overgrown, and falling apart.

Wheatley, a personality core on a management rail, finds you through a hole in the wall. He connects to your vault and drives it through the facility like a vehicle, smashing through corridors. When the vault crashes, you step out into the ruined Enrichment Center.

Key puzzles:

  1. Portal gun retrieval. Follow the linear path through decayed test chambers. Orange portals are pre-placed. Pick up the portal device in a ruined version of Portal 1's Chamber 02. You start with single-portal mode (blue only).
  2. Dual portal device. Reach the chamber where GLaDOS was defeated. The room is overgrown. Walk through it to trigger Wheatley's attempt to hack the system. He accidentally reactivates GLaDOS. She grabs you, crushes Wheatley, and drops you back into testing. You receive the full dual-portal device during the first proper test chamber.

The chapter is mostly linear. Follow Wheatley, walk through portals, and watch the story happen.

Chapter 2: The Cold Boot​

GLaDOS is back in control and angry. She puts you through a series of test chambers designed to reintroduce the core mechanics: portals, cubes, buttons, and flings.

Key puzzles:

  1. Cube redirection. Several chambers require portaling cubes to buttons in rooms you cannot walk to directly. Place a portal near the cube, another portal near the button, and push or carry the cube through.
  2. Fling chambers. Standard momentum puzzles. Deep pits with floor portals and wall portals aimed at your target. Same as Portal 1, but the geometry is less obvious.
  3. Laser introduction (late chapter). Your first Thermal Discouragement Beam. A laser fires across the room, and a catcher sits on the opposite wall. Redirect the beam using a portal pair: place one portal in the beam's path and the other portal on a surface that lines up with the catcher.
tip

GLaDOS comments on your performance constantly during this chapter. She is testing your patience as much as your puzzle skills. Her lines are worth hearing. Do not rush through chambers to skip dialogue.

Chapter 3: The Return​

Introduces Discouragement Redirection Cubes and Hard Light Bridges. Puzzles become multi-step.

Key puzzles:

  1. Laser cube routing. Pick up a Redirection Cube, carry it into the laser beam, and angle the redirected beam into the catcher. Later chambers require chaining two cubes or routing the beam through a portal before it hits the catcher.
  2. Hard Light Bridge traversal. A bridge extends from a wall emitter across part of the room, but not far enough. Place a portal in the bridge's path and another portal above the gap you need to cross. The bridge extends through your portal pair, creating a walkway.
  3. Bridge as shield. One chamber has turrets guarding the exit. Redirect a Hard Light Bridge between yourself and the turrets by placing a portal on the wall behind them. The bridge blocks their fire while you walk through.

Chapter 4: The Surprise​

Introduces Excursion Funnels. Puzzles combine funnels with portals for multi-layered traversal.

Key puzzles:

  1. Funnel riding. A funnel emitter pushes a beam across a gap. Step into the funnel and float across. The trick is placing a portal at the right point so the funnel redirects to a higher platform.
  2. Funnel polarity. Some chambers have a button that reverses the funnel direction. Float partway through the funnel, press the button (using a portal or a cube on a timer), and ride the reversed funnel to a new location.
  3. Aerial Faith Plates. Late in the chapter, Faith Plates appear. They launch you along fixed arcs. Place a portal at the landing zone to redirect your momentum to the actual exit.

Chapter 5: The Escape​

The narrative pivots. Wheatley reappears, badly damaged, and convinces you to sabotage GLaDOS. You go behind the scenes: turret manufacturing lines, neurotoxin generators, and control systems. Wheatley guides you through each sabotage step.

Key moments:

  1. Turret sabotage. You enter the turret production line and replace the template turret with a defective one. Follow Wheatley's instructions. The puzzle is navigating the factory, not solving a test chamber.
  2. Neurotoxin sabotage. Cut the neurotoxin supply by using a laser to sever the pipes. Redirect a Thermal Discouragement Beam through portals to hit the neurotoxin tube.
  3. The core transfer. Wheatley convinces you to perform a core transfer, swapping GLaDOS out of the mainframe and plugging himself in. The transfer succeeds. Wheatley takes control of the facility. GLaDOS is ejected into a potato battery. Then Wheatley goes power-mad almost immediately and punches you and potato-GLaDOS into the facility's deepest pit.
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Chapter 5 ends with a long fall. You cannot prevent it. The fall is scripted and leads directly into Chapter 6. Save before the core transfer sequence if you want to replay the dialogue.

Act 2: Old Aperture (Chapters 6 and 7)​

Chapter 6: The Fall​

You land in the abandoned lower levels of Aperture Science, built in the 1950s. The environment shifts from clean white panels to rusted metal, crumbling concrete, and overgrown test shafts. Pre-recorded audio logs from Aperture Science founder Cave Johnson play on speakers throughout the area.

This chapter introduces all three Mobility Gels.

Key puzzles:

  1. Repulsion Gel (blue). Your first gel encounter. Blue gel pours from a pipe onto a surface. Walk onto it and you bounce. The puzzle is coating the right surfaces to bounce yourself to higher platforms. Redirect the gel flow through portals: place one portal under the gel dispenser and another on the surface you want to coat.
  2. Propulsion Gel (orange). Orange gel coats floors to create speed runways. Sprint across a gel-coated floor, build speed, and jump or fling across gaps that are too wide for normal movement. Redirect gel through portals to coat floors in areas the dispenser cannot reach.
  3. Conversion Gel (white). The most important gel. White gel makes any surface portalable. In Old Aperture, almost no surfaces accept portals by default. Redirect white gel onto walls and floors to create your own portal locations. This changes the puzzle dynamic completely: you are building the puzzle's infrastructure, not just solving it.
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Gel dispensers always pour from above. Look up. If you cannot see a dispenser, it is behind a wall or above a ceiling that you need to portal through to reach. Place a portal under the dispenser's output and another portal on the surface you want to coat.

Chapter 7: The Reunion​

You climb upward through decades of Aperture Science history. The environment shifts from 1950s-era shafts to 1970s facilities to 1980s test chambers. Cave Johnson's audio logs become more desperate as the timeline progresses. GLaDOS (now a potato clipped to your portal gun) provides commentary.

Key puzzles:

  1. Multi-gel combinations. Chambers start combining gel types. Coat a wall with white gel to make it portalable, place a portal on it, redirect blue gel through the portal to coat a distant floor, then bounce off that floor to reach a high ledge.
  2. Gel and funnel combos. Redirect gel through Excursion Funnels. A funnel carries gel drops to surfaces that neither portals nor dispensers can reach directly.
  3. Large-scale traversal. The test shafts in Old Aperture are enormous. Multiple rooms connect vertically. You need to coat surfaces, place portals, fling, and gel-bounce across multi-room puzzles. If you lose track of the objective, look for the exit signs posted on the walls.

Story note: This chapter reveals that Cave Johnson ordered his assistant Caroline to be uploaded into the facility's AI. Caroline became GLaDOS. Potato-GLaDOS reacts to this discovery in real time. The dialogue in this chapter is some of the best in the game. Do not skip it.

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Stuck in the Pump Station Gamma elevator shaft? The transition from Chapter 6 to Chapter 7 puts you in a massive vertical shaft. The exit is near the ceiling. Look for portalable surfaces high on the interior walls. You need a large momentum fling to reach the top. The final portalable surface is angled at an awkward position near the very top of the shaft and requires a mid-air portal placement. Look higher than you think you need to.

Act 3: Wheatley's Facility (Chapters 8 and 9)​

Chapter 8: The Itch​

Back on the surface. Wheatley has taken over the facility and built his own test chambers. They are poorly designed: panels are misaligned, hazards are placed randomly, and the difficulty swings wildly. Wheatley provides commentary that reveals his growing instability and addiction to the testing euphoria.

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Expect a difficulty shift. Wheatley's chambers feel less intuitive than GLaDOS's. The visual language changes from "find the white panels" to executing blind mid-air funnel redirects and solving chambers with intentionally broken geometry. The puzzles require different spatial reasoning than anything before Chapter 8. This is by design, not a flaw. If you are struggling, check behind misaligned panels for the portalable surfaces Wheatley accidentally exposed.

Key puzzles:

  1. Broken chambers. Wheatley's test chambers use all the same elements (lasers, funnels, bridges, gels) but with intentionally bad design. The trick is that solutions often involve exploiting flaws in his construction: panels with gaps behind them, misaligned walls that expose portal surfaces, and shortcuts he did not intend.
  2. Frankenturrets. A turret fused with a cube. Walks around on cube legs. Pick it up and use it as a weighted object on a floor button.
  3. Increasing danger. Later chambers introduce real hazards: spike plates, masher traps, and bottomless pits that Wheatley claims are "part of the test." GLaDOS (still a potato) guides you through the worst of it.
warning

Chapter 8 has several chambers where panels shift mid-puzzle because Wheatley is actively restructuring the room. If the room layout changes while you are solving it, that is intentional. Adapt to the new configuration.

Chapter 9: The Part Where He Kills You​

The final chapter. Wheatley drops pretenses and tries to kill you directly. The facility is collapsing. This chapter is shorter but more intense than any previous chapter.

The boss fight:

Wheatley sits in the GLaDOS chassis at the center of a large arena. The fight has three phases, and each phase follows the same pattern:

  1. Attach corrupted cores. GLaDOS manufactures corrupted personality cores and drops them into the arena. Pick one up and attach it to Wheatley's chassis when prompted. Each core requires you to solve a mini-puzzle to reach Wheatley while he throws obstacles at you.
  2. Dodge hazards. Wheatley deploys bombs, turrets, and spike plates. Use portals and the arena's geometry to avoid damage.
  3. Bomb redirection. Wheatley throws bombs at you. Place a portal near the bomb, another portal near one of his exposed panels. The bomb passes through and damages him.

Between phases, Wheatley rearranges the arena. New hazards appear, and the safe zones shrink.

The ending:

After the third core attachment, a stalemate is declared. A button appears on the floor. Press it, and the system initiates a core transfer to remove Wheatley. Wheatley rigs the button with explosives. When you press it, the explosion blows a hole in the ceiling, exposing the night sky.

The ceiling shows the moon. Place a portal on the moon's surface. (The moon is made of moon rocks, which are portalable. Cave Johnson's audio logs in Old Aperture explained this: moon rock dust was the original ingredient for Conversion Gel.) Your other portal is on the arena floor. The vacuum of space pulls everything through the portal. Wheatley gets sucked into space. GLaDOS grabs you and pulls you back inside.

GLaDOS, restored to the mainframe, lets you go. She sends you to the surface in an elevator. The doors open to a wheat field. The Companion Cube lands beside you. The turret opera plays. Credits roll.

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The moon portal is the final action of the game. You have a short window to fire it after the ceiling breaks. If you miss, Wheatley kills you and you reload from the last checkpoint. Aim at the bright white circle in the sky and fire.

General Tips​

  • Look up. Dispensers, gel pipes, and portal surfaces are often on ceilings or high walls. The solution to most stuck moments is a surface you have not checked above you.
  • Listen to the audio. Cave Johnson's logs in Old Aperture tell you what the room is testing. The test name often hints at the mechanic you need.
  • Check behind panels. In Wheatley's chambers (Chapter 8), panels are misaligned. Look for gaps that show portalable surfaces behind the walls.
  • Quick-save before boss phases. Chapter 9 has long gaps between checkpoints. Press F6 at the start of each boss phase.